The core features of weight measurement technology have changed very little over the centuries. A balance yields a weight measurement relative to another object, while a scale can provide a measurement based on the deformation of a strain gauge load cell. Measurement accuracy has increased greatly with the advent of digital technology, but the underlying mechanisms are the same. For an individual to weigh an object or oneself, the individual must place the object or herself directly onto a scale to yield a measurement. The scale is always an external or third-party object relative to the individual seeking a weight measurement.
Contemporary weight measurement is based on the same technologies used thousands of years ago: a scale or a balance. The bathroom, kitchen, mailroom, and laboratory scales people are typically familiar with use some form of a strain gauge. A strain gauge operates as follows: 1) an object is placed on the scale; 2) a rod inside the scale deforms proportionally to the amount of force applied by the object; and 3) a mechanical or digital weight reading is displayed, notifying the user how much the object weighs. The primary advances in this technology over the past few hundred years have been in how accurately the scale can report the weight of the object.
While strain gauge-based scales may be adequate for many time-insensitive and traditional applications, they lack the ability to give the user measurements in a dynamic environment. The scale is a stationary instrument and compels the user to bring the object to be weighed to the instrument. Luggage scales are more mobile than other scales but lack precision and are awkward to use (for weighing luggage or any other object). Attempting a measurement of one or more objects (or persons) over a short period of time requires special and expensive infrastructure to be constructed around the scale, similar to the scales built around conveyor belts used by UPS®, FedEx®, and USPS®. In short, the scale is a third-party instrument relative to the user and the object to be weighed, and requires effort and special circumstances for its use.
Although there are other “smartshoes” on the market, these products have many of the same limitations as conventional weight measurement systems, e.g., traditional strain gauge scales. For example, prior art inventions at best can measure a qualitative change in pressure, not a quantitative, accurate, and precise measurement of weight and force.